John ohaeles tanner



(No Model.)

J. O. TAN'NER.

HYDRAULIC JACK.

No. 271,154. Patented Jan. 23,1883.

UNITED STATES PATENT OFFICE.

RICHARD DUDGEON, OF NEW YORK, N.

HYDRAULIC JACK.

SPECIFICATION forming part of Letters Patent No. 271,154, dated January 23, 1883.

' Application filed August 26, 1882. (No model.)

To all whom it may concern:

Be it known that I, J. O. TANNER, of Huntington, in the State of West Virginia, have invented certain new and useful Improvements in Hydraulic Jacks; and I do hereby declare that the following is at'ull, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form part of to this specification.

The objectof this invention is to facilitate the lowering of the jack and to admit of its rapid descent, thereby avoiding the delays in cident to the hydraulic jacks heretofore con- 1 structed, in which, as the plunger is lowered, the liquid passes up througha valved opening centrally located in the plunger. To such end I provide in the walls of the chamber in which the plunger works a series of longitudinal 2o grooves for the passage of the liquid, as hereinat'ter described, and illustrated in the annexed drawings, in which- Figure l is a longitudinal section through the hollow piston, with the plunger shown in elevation. Fig. 2 is a transverse section, on a somewhat enlarged scale, through the chamber in which the plunger works.

A indicates the piston-cylinder, and B the hollow piston, the head G of which is provided 0 with suitable packing, D, fitted upon a ring, 0, which is screwedmpon the piston-head.

E designates the plunger, which is vertically movable in a chamber, G, and is suitably packed. This plunger is fast on a rod, E,

which may receive vertical motion from any convenient motor. The wall of the chamber G is provided with a number of vertical grooves, H, which are of such length and so arranged that when the plunger E is at the lowest point of its stroke the upper termini of said grooves will be above the top of the plunger, thereby establishing free passages for fluid to rise Irom below above the plunger. An axial passage, f is made through the piston O, which is pro- 5 vided with a check-valve, 9, held to its seat by a spring, 8, applied in a central passage, which communicates with influx-passages, h h, through the plug 0. Between this plug Cl and the lower end of .the piston-head is a chamber, (letteredffi) which allows the checkvalve 9 to be depressed. This check-valve has a stem formed on it, the upper end of which extends a short distance in the chamber G for the purpose ot'allowing the plunger to strike it when the latter is at the terminus of its lower stroke, and thereby open the valve 9, and allow fluid to How from the space below the piston, through passages h h f f and grooves H, to the space above the plunger and piston. WVhen theplunger is raised above the upper termini of the grooves H the valve y will be closed by its spring 8, and no fluid will ascend through the piston-head. It will be found that by this arrangement the flow of water will be far more rapid, than heretofore, since in hydraulicjncks in which the plunger is provided with a valved opening the tendency of its valve. will be to partially close alter a certain quantity of water has accumulated above it, and hence considerable delay has been experienced; but by my improvement there is no upper valve to be weighted down, and hence no stoppage can occur.

Inthe drawings only so much of a hydraulic jack is shown as is necessary to illustrate my '75 invention, the construction and operation of such devices being well known.

Having thus described my invention, what I claim is- In a hydraulic jack, the combination of the So piston-cylinder, the hollow piston therein, the solid plunger-head therein, the piston-head, having passages hff and the spring-actuated check-valve g, with its trippingstem extcnil ing into chamber G, the inner walls of said chamber G having vertical fluid-passages H, all of said operative parts being contained within the piston-cylinder, and the whole being constructed and adapted to operate sub- .stantially in the manner and for the purposes 0 described.

In testimony that Iclaim the foregoing as my own I affix my signature in presence of two witnesses.

JOHN CHARLES TANNER. Witnesses:

JOHN MARTIN, GEO. 1*. BROWN. 

